Tecogalan is a novel angiogenesis inhibitor which possesses both in vitro and in vivo antitumor activity in a variety of tumor model systems and is isolated from a low molecular weight fraction of a sulfated polysaccharide produced by a bacterium, Arthrobacter sp. AT-25. This study is a phase I dose-finding trial with tecogalan in patients with solid tumors or Kaposi's sarcoma.